Markets open slightly higher as investors weigh productivity gain against geopolitical risks

U.S. stocks are opening slightly higher as investors weigh gains in productivity against worsening geopolitical concerns.

Among other things, investors were considering President Barack Obama's decision to authorize airstrikes in northern Iraq.

The Dow Jones industrial average rose 16 points, or 0.1 percent, to 16,383 in early trading Friday.

The Standard & Poor's 500 index rose two points, or 0.1 percent, to 1,911. The Nasdaq composite rose three points, or 0.1 percent, to 4,338.

In Europe, Germany's DAX was down 0.2 percent while the FTSE 100 index of leading British shares fell 0.4 percent.