* Yellen's comments on U.S. economy awaited
* Foreigners buy for fifth straight session
By Christine Kim
SEOUL, Feb 27 Seoul shares barely budged on Thursday morning as investors stepped to the sidelines amid escalating tensions in Ukraine and looked ahead to Federal Reserve Chair Janet Yellen's testimony before the Senate Banking Committee.
The Korea Composite Stock Price Index (KOSPI), ticked up 0.1 percent to 1,971.97 points as of 0235 GMT.
"Investors are taking a breather after the recent rise in the index and ahead of Yellen's comments," said Chang Hee-jong, an analyst at Hana Daetoo Securities.
Chang said the recent run of soft economic indicators from the U.S. has put a greater focus on the pending comments from the Fed chief.
Most analysts expect the Fed to maintain the pace of its stimulus-tapering, though a prolonged drought in confidence-boosting data could force the U.S. central bank to re-think its stance.
Markets were also keeping a weather eye on events in Ukraine, though the impact on Seoul was negligible so far.
"For now, tensions in Ukraine are not expected to have a big direct or indirect impact on the South Korean stock market," Chang said.
Foreigners extended their net buying for a fifth straight session, purchasing 23.6 billion won ($22.15 million) worth of stocks as of midday.
SK Holdings Co Ltd surged 6.4 percent in early trade after it announced it would be repurchasing more than 2.3 million shares of common stock to stabilise its stock price.
Solar energy-to-nanotechnology company Hanwha Chemical also rallied 5 percent on strong fourth-quarter earnings on top of local brokerage reports forecasting a turnaround in the solar energy sector.
Hyundai Merchant Marine Co Ltd fell 3.7 percent after a North Korean vessel crossed the maritime border between the two Koreas late on Monday, according to media reports on Wednesday.
Hyundai Merchant Marine Co Ltd is a logistics company and part of Hyundai Group, which has managed a number of projects in North Korea, including tourism.
Decliners outnumbered advancers 450 to 305.
The KOSPI 200 benchmark of core stocks was down 0.1 percent, while the junior KOSDAQ also edged 0.1 percent lower. ($1 = 1065.3000 Korean won) (Additional reporting by Jungmin Jang; Editing by Shri Navaratnam)