US STOCKS-Wall St ends lower after Yellen comments fail to inspire
* Yellen comments leave rate expectations unchanged on Wall Street
* Core inflation highest since January 2013
* Boeing falls after Bombardier jet report
* Microsoft down after report of Salesforce deal talks
* Indexes end down: Dow 0.29 pct, S&P 0.22 pct, Nasdaq 0.03 pct (Updates to close)
By Noel Randewich
May 22 (Reuters) - U.S. stocks ended weaker on Friday after Federal Reserve Chair Janet Yellen indicated that the central bank was poised to raise interest rates this year, in line with Wall Street's expectations.
Lackadaisical trading volume during the session ended a week of slow activity that has left many investors unconvinced that recent record-high levels are likely to last.
In a speech, Yellen said a rate hike would be warranted this year if the economy keeps improving as expected. She also said it would take several years to return to normal interest rates. Continuación...