City sources predict the FTSE 100 will open down 19 points from yesterday's close of 5,961 ahead of today's Consumer Price Index and Retail Price Index data as investors await fresh direction from the market. Advertising and media giant WPP is to buy a minority stake in Pakistan-based marketing agency Coverge Technologies for an undisclosed sum. The acquisition, which is to be made by a subscription for new shares, is already WPP's 10th of 2012. The firm, led by frontman Martin Sorrell, is making the purchase through its wholly-owned global advertising and communications company JWT.Guernsey-based property firm UK Commercial Property Trust saw its net asset value (NAV) per share ease a little in 2011 but its vacancy rate remained well below the industry average. NAV per share at the end of 2011 was 75.5p, down from 77.0p a year earlier, but with a dividend yield (as at the end of 2011) of 7.6%, the company could boast of a total return to shareholders over the year of 4.9%. The 2011 dividend has been maintained at 5.25p. Mining colossus Rio Tinto has announced a clutch of fixed rate bond issues with a weighted average maturity of 11.6 years. The offering comprises $500m of three-year, $500m of five-year, $1 billion of 10-year and $500m of 30-year debt securities, making $2.5bn in total. Coupons are as follows: Three-year = 12.125%; Five-year = 2.0%; 10-year = 3.5%; 30-year = 4.75%.