Blackstone Group LP, the world's largest private equity asset manager whose industry in the United States is in the political crosshairs, is seeking to prevent people from registering negative internet domains by acquiring them first.

Blackstone has registered several domain names critical of the buyout firm through MarkMonitor, a company that describes itself as an enterprise brand protection firm, a search of the domain database on whois.com showed on Tuesday.

Blackstone appears to have a sensitivity to criticism that it sucks. Variations of Blackstonesucks.com and StephenSchwarzmansucks.com were among those registered by MarkMonitor. Stephen Schwarzman is the co-founder and chief executive of Blackstone.

Registering defensive domain names is a very common practice for large brands. Defensive domain names can represent 90 percent or more of a large brand's portfolio, MarkMonitor spokeswoman Te Smith said, declining to comment specifically on Blackstone.

Rivals for the Republican nomination for the U.S. presidency are leading a full-blown assault on front-runner Mitt Romney's track record at private equity peer Bain Capital, leading the rest of the industry to fear collateral damage.

Private equity professionals are having to defend their record as job creators against popular criticism of them as asset-strippers in pin-striped suits, saddling companies with debt, selling their assets and taking dividends.

This is a routine defensive move to protect ourselves. Any company that is in the public eye will take similar measures, Blackstone spokesman Peter Rose said.

Still the firm may have some more domain registering to do to cover itself on that front. Although blackstonesucks.com may be taken, whois.com as of Tuesday showed blackstonesucks.net available for $9.88 per year.

Domain Name Wire reported on Blackstone's internet purchases earlier on Tuesday.

(Reporting by Greg Roumeliotis in New York; Editing by Tim Dobbyn)