CATCo Share News (CAT)

* Industrials lag on fears of global trade war

* Protectionist Navarro says he won't be new Trump econchief

* Oil drags down energy sector.

* Dow down 0.73 pct, S&P down 0.35 pct, Nasdaq up 0.1 pct(Updates to late afternoon, adds commentary, changes byline)

By Sinéad Carew

March 7 (Reuters) - Wall Street's three main indexes fell onWednesday as investors worried that U.S. President Donald Trumpwould deliver on his threat to impose steep import tariffs onimported steel and aluminum and cause a trade war after a keyadvisor resigned.

Investors also took the resignation, announced late Tuesday,of free trade supporter Gary Cohn from his position as Trump'stop economic advisor as a sign of conflict within the WhiteHouse, adding to the uncertainties over trade.

"Investors who were worried about a trade war before theresignation are even more worried now that a voice for freetrade has left the White House," said Paul Christopher,head of global market strategy at Wells Fargo InvestmentInstitute in St. Louis, Missouri.

Cohn, the architect of a tax overhaul passed in December,was seen as a stabilizing force within the Trump administration.His departure is seen strengthening the hands of thoseadvocating a protectionist agenda.

Spokeswoman Sarah Sanders told reporters the White House wason track to announce tariffs by the end of this week.

But markets trimmed losses after White House trade adviserPeter Navarro, who favors tariffs, said in a televisioninterview he was not a candidate to replace Cohn.

Cohn's exit made some investors less confident theadministration would be able to continue to implement itspro-business agenda, said Christopher.

"Investors tend to exaggerate political risks andunderestimate fundamental risks. We'd always put the economyfirst. The economy looks solid to us," he said.

On top of the steel tariffs, Trump also told China todevelop a plan to reduce its trade imbalance with the UnitedStates by a billion dollars.

At 2:44 p.m. ET, the Dow Jones Industrial Averagefell 182.57 points, or 0.73 percent, to 24,701.55, the S&P 500lost 9.67 points, or 0.35 percent, to 2,718.45 and theNasdaq Composite added 7.08 points, or 0.1 percent, to7,379.09.

In contrast, the Russell 2000 index, which tracksU.S. small-cap stocks, was up 0.5 percent as more domesticallyfocused companies are seen as having less exposure if foreigngovernments retaliate by slapping tariffs on U.S. exports.

The S&P energy sector was the biggest percentagedecliner of the S&P's 11 sectors with a 1.4 percent drop,weighed down by a 2.3 percent drop in oil prices from datashowing a rise in U.S. inventories and output.

Investors were also disappointed by Exxon's decisionnot to announce a share repurchase plan, sending it down 3.2percent.

Shares of U.S. manufacturers Boeing, down 1 percentand Caterpillar, down almost 2 percent, were hit byworries about higher input costs as well as potential exporttrade barriers.

Discount store operator Dollar Tree was down 15.4percent after reporting disappointing holiday quarter results,while off-price retailer Ross Stores fell 5 percentafter its full-year profit forecast came in largely belowexpectations.

Declining issues outnumbered advancing ones on the NYSE by a1.23-to-1 ratio; on Nasdaq, a 1.66-to-1 ratio favored advancers.

The S&P 500 posted 11 new 52-week highs and 3 new lows; theNasdaq Composite recorded 128 new highs and 18 new lows.(Reporting by Sruthi Shankar in Bengaluru; Editing by SrirajKalluvila and Chizu Nomiyama)